Data communication systems exchange user data to provide various services like media streaming, audio/video conferencing, data messaging, and internet access. The data communication systems use several communication networks to transfer the user data. In particular, the data communication systems use wireless networks to provide mobile and convenient access to their data services. Exemplary wireless communication protocols include Long Term Evolution (LTE) and Wireless Fidelity (WIFI). In wireless networks, the LTE and WIFI protocols typically carry the user data in Internet Protocol (IP) packets.
To implement wireless access, User Equipment (UE) and network base stations exchange wireless signals that transport user data and network signaling. The network base stations communicate with each other and core networks. Carrier Aggregation (CA) is often used on the wireless link between the UEs and the network base stations.
CA allocates additional bandwidth to UEs and relays in the form of Orthogonal Frequency Division Multiplex (OFDM) resource blocks. These simultaneous OFDM resource blocks may be contiguous and non-contiguous, and they may be intra-band or inter-band. Thus, the base stations and UEs exchange user data over parallel streams by using multiple CA resource blocks per OFDM time period.
To extend wireless access beyond the network base stations, wireless relays are deployed between the UEs and the base stations. The wireless relays exchange the user data between the UEs and the network base stations to extend data services like internet access, voice calling, and video conferencing to these UEs. CA is also used between the UEs and wireless relays, and between the wireless relays and the network base stations.
CA requires the various receiving devices to return acknowledgement signals (ACKs). The ACK load may become oppressive, especially for Downlink (DL) CA that transmits the ACKs on a thin Uplink (UL). Network base stations may turn CA off in times of radio interference, buffer overload, and the like. Unfortunately, network base stations do not effectively and efficiently control CA in wireless networks that use wireless relays.